Wireless Link Range

d = f(Ptx, Gtx, Grx, sensitivity, freq)

Calculator

Result
—

Formula

d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km

Description

This formula estimates the maximum free-space communication range based on the Friis transmission equation rearranged to solve for distance. It accounts for transmit power, antenna gains on both ends, receiver sensitivity, and operating frequency. The result represents ideal line-of-sight range without obstructions, multipath, or atmospheric absorption. Real-world range is typically 30-70% of the free-space calculation due to ground reflections, building penetration losses, and fading margins.

Variables

  • d — Maximum range (m)
  • Ptx — Transmit power (dBm)
  • Gtx — Transmit antenna gain (dBi)
  • Grx — Receive antenna gain (dBi)
  • sensitivity — Receiver sensitivity threshold (dBm)
  • f — Operating frequency (Hz)

Practical Notes

Add a fade margin of 10-20 dB for reliable outdoor links and 20-30 dB for indoor environments. Higher frequencies experience greater free-space path loss, which is why sub-GHz bands like 433 MHz and 868 MHz achieve longer range than 2.4 GHz for the same power and antennas.

Related Formulas

UART Baud Rate Error RS-485 Termination Resistor RS-485 Bias Resistor Shannon Channel Capacity Bit Error Rate (BPSK) Manchester Encoding Bandwidth

Need more features?

Save calculations, import telemetry data, simulate battery discharge, and collaborate with your team.

Try the App